Vaporizer for insecticides and the like



Oct. 28, 1952 J. LAlBow VAPORIZER FOR INSECTICIDES AND THE LIKE FiledJune 20, 1951 INVENTOR Jubsaiawt figg Patented Oct. 28, 1952 VAPORIZERFOR INSECTICIDES AND THE LIKE Jules Laibow, Merchantville, N. J.,assignor to Cardinal Chemical Corporation, Philadelphia, Pa., acorporation of Pennsylvania Application June 20, 1951, Serial No.232,539

4 Claims. 1

The present invention relates generally to vaporizers for insecticidesand the like and it relates more particularly to insecticide-vaporizerswherein a hermostatically-controlled electrical heating elementmaintains the temperature within a given range calculated to causevaporization of the insecticide at a predetermined rate.

An object of the present invention is to provide a new and improvedvaporizer for insecticides and the like. Another object of the presentinvention is to provide a novel insecticide-vaporizer which is simpleand easy to manufacture, relatively inexpensive and yet accurate anddependable in operation, durable and at the same time so constructedthat those parts which are capable of failure through accident or longuse can be readily replaced.

Other objects and advantages of the present invention are apparent inthe following detailed description, appended claims and accompanyingdrawings.

It has been known for many years that rooms can be kept free of flies,mosquitoes and other insects, without harmful effects upon humans ordomestic animals, by spraying or vaporizing therein such insecticides asDDT and lindane (which is the gamma isomer of hexachlorocyclohexane). Ithas also long been known that a particularly effective way to vaporizethese insecticides is to heat them at relatively moderate temperaturesso as to cause the materials (which are substantially non-volatilesolids at room temperature) to vaporize gradually in the form of anaerosol and to give a suiciently high concentration in the air to belethal to insects while being harmless to humans and animals and withoutcontamination of foods being stored or prepared in the room. While manydifferent types of insecticide-vaporizers have been suggested in thepast, none of them has proven entirely satisfactory or acceptable.

Accordingly. the present invention contemplates a. new and improvedelectric vaporizer designed particularly for the relatively slow,controlled vaporization of insecticides which is simple and yetdependable in operation, and which is so constructed and arranged thatthe heating unit, thermostatic control and insecticide container caneach be readily replaced if it becomes defective due to prolonged use oraccident.

Generally speaking, the novel vaporizer of the present inventionincludes a frame or housing having an open-top bowl, containing aremovable generally disc-shaped hot-plate which is diametricallyapertured to receive a removable cartridge-type heating element andwhich has a self-contained thermostat element fastened to its underside,and a cup for insecticide positioned within the bowl and seated upon thehot-plate; the bowl being provided with a peripheral collar or lid whichnormally holds the cup securely in place but which can be detached topermit removal of the cup.

For the purpose of illustrating the invention, an embodiment which ispresently preferred is shown and described herein, it being understood,however, that the invention is not limited to the precise arrangementsand instrumentalities disclosed.

Referring to the accompanying drawings, in which like referencecharacters indicate like parts throughout:

Figure 1 is a perspective view of a vaporizer forming one embodiment ofthe present invention.

Figure 2 is a top plan View of the embodiment of Fig. 1.

Figure 3 is another view, partly in side elevation and partly invertical cross-section of the embodiment of Fig. 1.

Figure 4 is an exploded perspective view of the hot-plate andheating-element.

Figure 5 is a fragmentary perspective view of the inside of the bowlshowing a detail of the hot-plate supporting structure.

According to the embodiment of Figs. 1-5, the novel vaporizer of thepresent invention may include a more or less integrally formed housingof metal or the like, which is indicated generally by the referencecharacter I0. The housing I0 contains various features of ornamentationwhich are the subject of my co-pending application, Serial No. D.15,613, filed simultaneously herewith, now Design Letters Patent D.164,242, granted Aug. 14, 1951.

The housing I0 includes a generally iiat endplate II, which is adaptedto be fastened to a wall or other vertical supporting surface in anysuitable manner, as for example by means of a wall-plate I2 having anupwardly directed and tapered tongue I3 of trapezoidal cross-section,which is adapted to make detachable Vengagement with a correspondinglyshaped undercut groove I4 in the end-plate II. The housing I0 alsoincludes a hollow arm I5 which extends generally horizontally from theend-plate II and a hollow, open-top, downwardly tapered bowl I 6, formedat the outer end of, and in communication with, the arm I5. An opening34 is provided in the housing I 0. at the bottom of the 3 bowl I6, topermit convection-flow of air through the bowl as will be described morefully hereinbelow.

Integrally formed on the inside of the bowl I6 are a plurality (forexample three) of circumferentially distributed, inwardly extending lugsI1 whichjare shown in dotted-lines in Fig. 2, and one of which 'is shownin Fig. 5. The lugs I'I are kerfed or notched at their inner free endsto provide centering supporting shoulders I8 for a separate removablegenerally disc-shaped hotplate I9. As shown more particularly in Figs. 3and 4, the hot-plate I9 is provided with 'a central opening 29 extendingdiametrically therethrough, and a generally segment-shaped notch 2Iintersecting one end of the opening l251|. The hot-plate I9 is adaptedto be .positioned upon the shoulders I8 of the lugs I1, with the 'notch2| adjacent the arm I5, as shown in Fig.. 3.

A generally cylindrical cartridge-like heatingelement 22 is constructedand arrangedremovably to Abe inserted within the opening 29 as indicatedin Figs. 3 Vand 4. 'The heating-element 22 is of conventionalconstruction -con taining electrical resistance wiring (not shown) andis connected in series with a conventional make-and-breakthermostat-unit 23 which is fastened to the underside of the hot-platei9 by a metal-strap -24 and screws 25. To the heatingelement 522 andthermostat-unit 23 are connected the wires of` an electric-cord 26 whichextends through 4Vthe hollow arm I5 and emerges through a slot 2"!formed in thebottomof the end-plate II; the free end of theelectric-cord carrying a conventionalplug 28 for detachable connectionto any electric socket (not shown) so as to energize the heating-element22.

AThethermotat-.unit23 .is vof the pre-set type adapted tomaintain thehot-plate I9 .at a predetermined temperature (plus or minus a .fewdegrees) by breaking the circuit tothe .heatingelement 22 when thehot-plate temperature exceeds the predetermined value and by re-closingthe circuit vwhen the hot-plate temperature falls belowthe predeterminedvalue.

Seated upon the hot-plate I9 is a cup or dish 29 intended to hold theinsecticide or fumigant or the like to be volatilized. The cup 29 may beof heat-proof glass or other suitable chemicallyresistant andheat-resistant material and is'somewhat smaller in maximum diametervthan the insideof the bowl `I6 so as toprovide an annular cle'ancetherebetween.

A peripheral lid or collar'il, having inner and outer downturnedannularflanges 3| .and -32, is fastened to the top of th-ebowl AIt by screws33, so `as to overlie the rimsof the bowland the cup 29, as indicatedinFig. 3. However, a slight clearance is provided between the lid 39 andthe vrim of the 'cup 29, as also indicated in Fig. 3.

With the vaporizer plugged in and operating, air Tfrom -the 'roomientersl the bowl i 9 I through an inlet-opening 3'4 formed in fthe'bottomthereof and rises, through convection, fto pass through the clearancesintermediate the 'cup 29 and the bowl I6 and lid/39, 'to sweep acrossthe surface of the material being volatilized inthe cup, and nally -toemerge through the -central opening 35 of the 1id-3'9,` as indicatedbythe'arrows'in Fig. 3.

rIhis not only v.prevents overheating or fthe heating-unit 22 andhot-plate l 9, but also v:facilitates volatilization of theheated-insecticide'in a manner well knownto 'those skilledin the art,vand thereby enables the vaporizer to operate at la somewhat `lowertemperature setting :than would ythe cup 29, the screws 33 and lid 39are removed and the cup simply lifted out.

`Should it become necessary to replace the heating-element 22 orthermostat-unit 23, the lid 39 and cup 29 are removed as describedabove, whereupon the hot-plate i9 is pulled out of the top of the bowl.

As indicated in Fig. Li, the heating-element and the thermostat-unit 23are thus exposed for ready vdisconnection and replacement,

by merely cutting and re-connecting the wires (and, in the case of thethermostat-unit, by removing and then replacing the strap 24 and screws25).

The housing may be formed inexpensively from light-Weight aluminum alloyor from steel or the like in any suitable manner, as for example bydie-casting left and right longitudinal half-sections and welding .themtogether into-an integral unit.

The heating-element'22 is-a self-contained unit, the wiring of which isfully shielded-and requires no exterior electrical insulationintermediate the heating-element and the hot-plate, such as lisordinarily required to `prevent short-circuiting. Similarly, thethermostat-unit is self-contained and `electrically shielded andrequires insulation only at the soldered conn'ectionsof the wiresto itsterminal-posts. i

The present invention may be embodied in other spe'cic forms and,accordingly, the abovedescribed embodiment is to be considered-merely asillustrative and not restrictive, referencefbeing made to the appendedclaims, rather than to the foregoingdescription, as indicating the'scopeof the invention.

--Having thus described-my invention, IA claim as new and desire-toprotect by Letters Patent:

-1. In-a vapori-zer Ifor insecticides and the like, a generallyhorizontalhousing havin-g a. generally upright open-top bowl formed atits end, a generally disc-shaped hot-plate horizontally -positionedwithin said bowl and removable therefrom, said hot-plate being disposedat a level substantially below'the top of the bowl but substantiallyabove the bottomvthereotsaid hot-plate having a radial-openingformed'therein, a self-contained generally cylindrical cartridge-type`electrical 'heating `element removably positioned within' said radialopening, a Self-contained*thermostat-unit connected tothe underside ofthe hot-'plate'and removable from the bowl therewithfsaidthermostat-unit being operatively kconnected to the heating-element soas to make and -breakjth'e electricaly circuit theretov and thereby tomaintain' the hot-plate within a predetermined vtemperature range, and acup for insecticide or the like 4re movably disposed-within the upperportion of the bowl'above the'hot-plate, the cup'being spaced away fromthe inner wall of thebowl to provide an annular clearance therebetween,lthe bowl havingv a bottom opening formed therein,-whereby air canenterthe bowl `and pass upward through the bowlbyzconvection across thehot-plate'an'd throughsaid annular clearance, to emerge from theopen-top ofl-thelbowl.

l2. Al construction according to claim lwheren the top of the bowl isprovided with a detachable peripheral lid extending inward beyond therim of the cup and having a downwardly-directed inner annular flange anda central opening, whereby the convection flow of warm air is deflectedradially inward and across the surface or the insecticide in the cupbefore emerging from the central opening of the lid.

3. In a vaporizer for insecticides, a housing having a generallyhorizontally extending arm adapted tc be secured at one end to a wall orthe like and a generally upright dovrnwardly tapered open-top bowlformed at the other end of the arm, a heating member removably mountedwithin the upper portion ci said bowl, said heating member including agenerally horizontal hotplate disposed somewhat below the top of thebowl and a self-contained heating element disposed within the hot-plate,a cup for insecticide resting upon and supported by said heating memberwith the bottom of the cup disposed above the hotplate and adapted to beheated thereby and with the rim of the cup disposed slightly below thetop or" the bowl, the cup being removable from the bowl independently ofthe heating member, and a self-contained thermostat mounted on theunderside of the heating member and removable from the bowl therewith,said thermostat being operatively connected to the heating element so asto regulate the operation thereof and thereby to maintain the contentso1" the cup within a predetermined temperature range.

4. A construction according to claim 3 wherein annular clearances areprovided intermediate the heating element and cup and the bowl, andwherein the bowl is provided with a bottom opening, whereby air canenter the bottom or the bowl and pass upward therethrough by convectionto emerge from the open-top of the bowl generally peripherally of thecup.

JULES LAIBOW.

REFERENCES CTED The following references are of record in the le of thispatent:

UNTED STATES PATENTS OTHER REFERENCES Chrornalox, Catalog 50, reprintMarch 1959, Edwin L. Wiegand Co., 7500 Thomas Blvd., Pittsburgh 8,Pennsylvania, page 10, relied upon.

